The long-term objective of the project continues to be the development of a behavioral weight control program for obese patients with Type II diabetes. The proposed study is designed to investigate the effect of exercise, as an adjunct to caloric restriction, in the treatment of Type II diabetes, and, specifically, to determine whether there are dose-response relationships between the amount of exercise expenditure included in the program and changes in body weight or metabolic control. The effect of involving the spouse in the treatment program on long-term adherence to diet and exercise will also be assessed. One hundred fifty obese patients with Type II diabetes will be randomly assigned to behavioral weight control programs varying in the amount of caloric expenditure from structured exercise (O, 450, or 900 calories/week) and in the amount of spouse support (spouse included in assessments and treatment or spouse included in assessments only). Fitness, eating habits, serum lipids, blood pressure, and blood sugar control will be measured at pretreatment, the end of the 15-week program, and at 1-year follow-up. The proposed project will also analyze individual differences which may affect weight loss and/or the metabolic response to weight loss and will study the relationship between spouse pairs in pretreatment eating and exercise behaviors, and in the magnitude of habit change during treatment.